Police spokesman Ayyoub Abu Shaar said Sunday that authorities uncovered the ring last week when they traced a man trying to distribute a counterfeit 100 shekel bill last week. The Palestinian territories use Israeli currency for many transactions.

The man led authorities to a gang and some 20 million shekels, or roughly $5.5 million, in fake bills. Abu Shaar says the money was confiscated before it was put into circulation.

Abu Shaar says police have arrested four people so far, and confiscated equipment including printers, laptops, ink and paper.

It is the largest counterfeiting ring discovered in Gaza since Hamas took control in 2007.